What are the potential risks of being logged in and visiting other websites while using a PHP application?

When a user is logged in to a PHP application and visits other websites, there is a risk of session hijacking or cross-site scripting attacks. To mitigate this risk, it is important to properly secure the session handling and sanitize user input to prevent malicious code execution.

// Set session cookie parameters to prevent session hijacking
ini_set('session.cookie_httponly', 1);
ini_set('session.cookie_secure', 1);

// Sanitize user input to prevent cross-site scripting attacks
$user_input = htmlspecialchars($_POST['user_input'], ENT_QUOTES, 'UTF-8');